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Mamiya Sekor 55mm f1.8
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PostPosted: Sun Feb 09, 2014 9:25 am    Post subject: Mamiya Sekor 55mm f1.8 Reply with quote

We have been out all day and returned late this afternoon.
I packed my trusty K-10D with Mamiya Sekor 55/1.8 this morning but never got a chance to use it all day (went to Coffs Harbour and back - long story).
However just before we left this morning, there was an early shaft of light that illuminated this humble nasturtium.
Just thought I would share it here.
OH



Crop:



PostPosted: Sun Feb 09, 2014 10:02 am    Post subject: Reply with quote

awesome colors!


PostPosted: Sun Feb 09, 2014 10:11 am    Post subject: Reply with quote

Really like that.

It's great being in just the right place at the right time Smile


PostPosted: Sun Feb 09, 2014 10:20 am    Post subject: Reply with quote

Yes -- here in Essex England we have forgotten what 'Sunlight' looks like -- only RAIN if you want some !


PostPosted: Sun Feb 09, 2014 10:29 am    Post subject: Reply with quote

pentaxpete wrote:
Yes -- here in Essex England we have forgotten what 'Sunlight' looks like -- only RAIN if you want some !


Thanks folks for the kind words.
We are desperate for rain in Australia.
The whole country is effectively in drought, with farmers having to destroy stock for lack of feed.
Extremely hot as well. Temps around the 40+ degrees C mark (104+F) daily with no end in sight for another month at least.
Yes please - send us some of your rain and you can have some of our sunshine gladly.
Back to the lens - it is pleasing in its colours I think, like most Mamiyas.
OH


PostPosted: Sun Feb 09, 2014 11:28 am    Post subject: Reply with quote

Very nice lens indeed - imho a little underrated. Works fine on my Nex-6.


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Last edited by wolfhansen on Fri Nov 17, 2017 8:01 am; edited 1 time in total


PostPosted: Sun Feb 09, 2014 1:29 pm    Post subject: Reply with quote

Nice photo.
Glad you made the effort to take it.


PostPosted: Sun Feb 09, 2014 7:29 pm    Post subject: Reply with quote

Wonderful images


PostPosted: Mon Feb 10, 2014 4:15 am    Post subject: Reply with quote

wolfhansen wrote:
Very nice lens indeed - imho a little underrated. Works fine on my Nex-6.







Agreed.
There seems to have been a renewed growth in interest in Mamiya glass recently.
Well deserved IMHO.
OH


PostPosted: Mon Feb 10, 2014 12:16 pm    Post subject: Reply with quote

Great light! Nice lens.

I also like my copy a lot.

And yes, please send some sunshine over here to Germany as well.


PostPosted: Tue Nov 14, 2017 5:58 am    Post subject: Reply with quote

We lost the images from this thread some time back.
I have decided to shoot some new ones.
All at widest aperture and from my back yard of course.
Here we go
Tom


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PostPosted: Tue Nov 14, 2017 11:53 am    Post subject: Reply with quote

I have only one Mamiya-Sekor lens (135mm) and it, too, produces lovely colors.


PostPosted: Tue Nov 14, 2017 12:46 pm    Post subject: Reply with quote

Nice photos!
Like 1


PostPosted: Thu Nov 16, 2017 11:41 pm    Post subject: Reply with quote

Which version, the 6/4 or the 6/5?


PostPosted: Fri Nov 17, 2017 4:48 am    Post subject: Reply with quote

papasito wrote:
Which version, the 6/4 or the 6/5?


Good question - how do I tell them apart?
Tom


PostPosted: Fri Nov 17, 2017 8:04 am    Post subject: Reply with quote

Thomas, thanks for the reminder - pictures restored


PostPosted: Fri Nov 17, 2017 8:08 am    Post subject: Reply with quote

wolfhansen wrote:
Thomas, thanks for the reminder - pictures restored


Like 1 Like 1 Like 1


PostPosted: Fri Nov 17, 2017 7:24 pm    Post subject: Reply with quote

Oldhand

As you sure know, can do that:

1- Put the lens in front of a light source (window can be used)

2- You can stay in front of the lens, so you can see only the front of it.

2- Close the aperture ring to the minimun.

3- See how many reflexions of the frontal part are there

4- 6 Reflexions: a 6/5 formula lens (AFAIK, the best one)

5- 5 Reflexions: 6/4 formula lens (very good one too)


PostPosted: Fri Nov 17, 2017 8:13 pm    Post subject: Reply with quote

papasito wrote:
Oldhand

As you sure know, can do that:

1- Put the lens in front of a light source (window can be used)

2- You can stay in front of the lens, so you can see only the front of it.

2- Close the aperture ring to the minimun.

3- See how many reflexions of the frontal part are there

4- 6 Reflexions: a 6/5 formula lens (AFAIK, the best one)

5- 5 Reflexions: 6/4 formula lens (very good one too)


Thank you papasito.
If I am counting correctly it has six reflections, but it is the same as Wolfgang's lens shown above in his post.
Cheers
Tom


PostPosted: Fri Nov 17, 2017 9:18 pm    Post subject: Reply with quote

Wolfgang's lens is an chromer aperture ring, so a TL lens.

If you want to and can do, should post an image with the 6 reflexions. It will be very informative for the mamiya history.

Note that some papers do not say nothing about the last DTL lens with the 6/5 formula.

A lot more can be ignorated about that lens.


PostPosted: Sat Nov 18, 2017 4:17 am    Post subject: Reply with quote

papasito wrote:
Wolfgang's lens is an chromer aperture ring, so a TL lens.

If you want to and can do, should post an image with the 6 reflexions. It will be very informative for the mamiya history.

Note that some papers do not say nothing about the last DTL lens with the 6/5 formula.

A lot more can be ignorated about that lens.


OK, here are some pictures of the lens.


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Aperture open
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Aperture closed
#3


PostPosted: Thu Mar 07, 2019 1:22 am    Post subject: Reply with quote

I'm curious, what is the interpretation from oldhand's images posted above?

I understand that the elements and groups cause reflections, therefore the number of visible reflections should indicate lens structure.

But this thread seems to simply stop without a acknowledging the images posted above.

If a 55/1.8 is a 6/4, are there two groups in front of the aperture and two groups behind it?
If a 55/1.8 is a 6/5, are there three groups in front of aperture and two behind?

If that's how it works, then oldhand's chrome-nose seems to be a 6/5 because it shows three groups in front of the aperture. Is that correct?

I'm just trying to fully understand.

Also, while reading about this subject, I found various vintage DTL advertisements and manuals that all show the DTL with chrome-nose lenses, so I am not so sure that chrome must be TL and black must be DTL. Is it possible that chrome-nose lenses extended into the DTL series?

I'm not sure I grasp the concept that a certain few 'late model' all-black DTL 55/1.8's have a fortunate 6/5 configuration but the rest do not.
M/S changed lens and camera designs much more often for SLR cameras than did any other maker.
It seems strange that they would have complicated matters further by also changing internal glass arrangements mid-series.

As a relative newcomer, I have much to learn, but I wouldn't mind seeing photographic evidence that some DTL black 55/1.8 lenses had a different glass configuration than others.

Lastly, SX lenses are much lighter than DTL lenses. Does this further complicate the suggestion that late DTL black 55's had an SX glass arrangement.

Not trying to stir a pot, just looking for concrete information.

Thanks!


PostPosted: Thu Mar 07, 2019 1:50 am    Post subject: Reply with quote

Yes, it would appear to me that the six reflections indicate three groups in front.
I cannot understand how five reflections can exist - I expect that two groups will show four reflections
Tom


PostPosted: Thu Mar 07, 2019 3:22 pm    Post subject: Reply with quote

3 elements in 3 grupos show 6 reflexes

3 elements in 2 grupos show:

A-1 element (the first) only shows 2 reflexes

B-The 2 elements stuck together, show 3 reflexes.

A + B = 5 reflexes


PostPosted: Thu Mar 07, 2019 6:53 pm    Post subject: Reply with quote

papasito - from oldhand's photographs above, can you say what is the configuration of his lens?

Can you explain more about reflections with aperture-open vs aperture closed?

Thanks.

I can understand the theoretical basis of your comments on this thread, but I still do not understand the practical application.

Maybe it will help if you use his example/

Thanks! I appreciate it.